(answered) 
the simulation kept track of the variables and automatically recorded data on object displacement, velocity, and momentum. if the trials were run on a real track with real gliders, using stopwatches and meter sticks for measurement, how might the data compare? check all that apply.
this- there would be variables that would be hard to control, leading to less reliable data
- the data would be just as valid if it were recorded with a stopwatch.
this- meter sticks may lack precision or may be read incorrectly.
this-  real glider data may vary since real collisions may involve loss of energy.
this human error in recording or plotting the data could be a factor.
- controlling real glider velocities by hand would be just as accurate as simulation controls.

it is easily magnetized.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia

a 2,000 calorie based diet.